(function(f) {

    'use strict';
  
    /* istanbul ignore else */
    if (typeof exports === 'object' && exports != null &&
        typeof exports.nodeType !== 'number') {
      module.exports = f ();
    } else if (typeof define === 'function' && define.amd != null) {
      define ([], f);
    } else {
      var base64 = f ();
      var global = typeof self !== 'undefined' ? self : $.global;
      if (typeof global.btoa !== 'function') global.btoa = base64.btoa;
      if (typeof global.atob !== 'function') global.atob = base64.atob;
    }
  
  } (function() {
  
    'use strict';
  
    var chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
  
    function InvalidCharacterError(message) {
      this.message = message;
    }
    InvalidCharacterError.prototype = new Error ();
    InvalidCharacterError.prototype.name = 'InvalidCharacterError';
  
    // encoder
    function btoa(input) {
      var data = String (input), o1, o2, o3, bits, i = 0, acc = '';
  
      while (i < data.length) {
        // pack three octets into four hextets
        o1 = data.charCodeAt (i++);
        o2 = data.charCodeAt (i++);
        o3 = data.charCodeAt (i++);
  
        if (o1 > 128 || o2 > 128 || o3 > 128) {
          throw new InvalidCharacterError ("'btoa' failed: The string to be encoded contains characters outside of the Latin1 range.");
        }
  
        bits = (o1 << 16) | (o2 << 8) | o3;
        // use hextets to index into b64, and append result to encoded string
        acc += chars.charAt ((bits >> 18) & 0x3F) +
               chars.charAt ((bits >> 12) & 0x3F) +
               chars.charAt ((bits >>  6) & 0x3F) +
               chars.charAt ((bits)       & 0x3F);
      }
  
      switch (data.length % 3) {
        case 0: return acc;
        case 1: return acc.slice (0, -2) + '==';
        case 2: return acc.slice (0, -1) + '=';
      }
    }
  
    // decoder
    // [https://gist.github.com/1020396] by [https://github.com/atk]
    function atob(input) {
      var str = (String (input)).replace (/[=]+$/, ''); // #31: ExtendScript bad parse of /=
      if (str.length % 4 === 1) {
        throw new InvalidCharacterError ("'atob' failed: The string to be decoded is not correctly encoded.");
      }
      for (
        // initialize result and counters
        var bc = 0, bs, buffer, idx = 0, output = '';
        // get next character
        buffer = str.charAt (idx++); // eslint-disable-line no-cond-assign
        // character found in table? initialize bit storage and add its ascii value;
        ~buffer && (bs = bc % 4 ? bs * 64 + buffer : buffer,
          // and if not first of each 4 characters,
          // convert the first 8 bits to one ascii character
          bc++ % 4) ? output += String.fromCharCode (255 & bs >> (-2 * bc & 6)) : 0
      ) {
        // try to find character in table (0-63, not found => -1)
        buffer = chars.indexOf (buffer);
      }
      return output;
    }
  
    return {btoa: btoa, atob: atob};
  
  }));